Use FFmpegVideoDecoder from a UtilityProcess

media/mojo/common/mojo_shared_buffer_video_frame.h

Index: media/mojo/common/mojo_shared_buffer_video_frame.h
diff --git a/media/mojo/common/mojo_shared_buffer_video_frame.h b/media/mojo/common/mojo_shared_buffer_video_frame.h
index 945f43e51f38ec57e6279a8e8e9538d6e7772fd7..028dbf86823f278cf9c19848549a747a9564ad97 100644
--- a/media/mojo/common/mojo_shared_buffer_video_frame.h
+++ b/media/mojo/common/mojo_shared_buffer_video_frame.h
@@ -12,6 +12,7 @@
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
 #include "media/base/video_frame.h"
+#include "media/base/video_frame_pool.h"
 #include "mojo/public/cpp/system/buffer.h"
 #include "ui/gfx/geometry/rect.h"
 #include "ui/gfx/geometry/size.h"
@@ -29,6 +30,21 @@ namespace mojom {
 class VideoFrame;
 }
 
+class MojoVideoFramePoolDelegate final : public VideoFramePoolDelegate {
+ public:
+  ~MojoVideoFramePoolDelegate() override;
+
+  scoped_refptr<VideoFrame> CreateZeroInitializedFrame(
+      VideoPixelFormat format,
+      const gfx::Size& coded_size,
+      const gfx::Rect& visible_rect,
+      const gfx::Size& natural_size,
+      base::TimeDelta timestamp) override;
+
+  scoped_refptr<VideoFrame> WrapVideoFrame(
+      const scoped_refptr<VideoFrame>& frame) override;
+};
+
 // A derived class of media::VideoFrame holding a mojo::SharedBufferHandle
 // which is mapped on constructor and remains so for the lifetime of the
 // object. These frames are ref-counted.
@@ -40,6 +56,15 @@ class MojoSharedBufferVideoFrame : public VideoFrame {
       base::Callback<void(mojo::ScopedSharedBufferHandle buffer,
                           size_t capacity)>;
 
+  static scoped_refptr<MojoSharedBufferVideoFrame>
+  WrapMojoSharedBufferVideoFrame(
+      const scoped_refptr<MojoSharedBufferVideoFrame>& frame);
+
+  static scoped_refptr<MojoSharedBufferVideoFrame> CreateYUV(
+      VideoPixelFormat format,
+      const gfx::Size& dimensions,
+      base::TimeDelta timestamp);
+
   // Creates a new I420 frame in shared memory with provided parameters
   // (coded_size() == natural_size() == visible_rect()), or returns nullptr.
   // Buffers for the frame are allocated but not initialized. The caller must